Speed-indicator.



W. H. ZACHMANN. SPEED INDICATOR.

APPLICATION FILED JUNE 27, 1913.

Patented May 30, 1916.

1 VI 1 5% S in m m INVENTOR ATTORNEY WITNESSES .shall thereafterclaims.

UNITED STATES PATENT onnron.

WILLIAM H. ZACHMANN', OF WOODHAVEN, NEW YORK, ASSIGNOR TO AMERICAN EVER READY COMPANY, A CORPORATION OF NEW YORK.

SPEED-INDICATOR.

Application filed June 27, 1913.

To all whom it may concern:

Be it known that I, WVILLIAM H. ZACH- MANN, a citizen of the United States, residing at l/Voodhaven, in the county of Queens and State of New York, have invented certain new 'and useful Improvements in Speed-Indicators, of which the following is a specification, reference being had therein to the accompanying drawings, forming part thereof.

My invention relates to thattype of speed indicator commonly known as a revolution counter and employedfor determining the number of rotations of a rotating part, such as a rotating shaft, in a given interval of time, for example, for counting the rotations during a minute and thereby directly ascertaining the R. P. M. of the shaft or appear from the following description.

I shall now describe the revolution counter embodying my invention illustrated in the accompanyingdrawings and point out my invention in Figure '1- is a side elevation with one side of the casing removed and with parts in section, showing the actuating mechanism in non-operative condition. Fig. 2 is a section on a vertical plane indicated by the line 22 of Fig. 1 as viewed from the left. Fig. 3 is a section on a horizontal plane indicated by the line 3-3 of Fig. 1 as viewed from below. Fig. 4: is a section similar to Fig. 2, with parts omitted, but showing the actuating mechanism in operative condition.

A frame or casing 5 of convenient shape for grasping in the hand has journaled therein, in suitable bearings, a counter operating rotative shaft or spindle 6, and carries the counting mechanism, between which Specification of Letters Patent.

Patented May 30, 1916.

Serial No. 77 ,077.

and the shaft 6 is the actuating mechanism involving the present invention.

The counting mechanism may be of any suitable construction and in the device embodying my invention illustrated in the drawings comprises a series of coaxial number wheels, including a units number wheel 7 from which step-by-step rotation is imparted successively to the other number wheels by means of suitable connections, as indicated in the drawings. The provision of suitable means for resetting the number wheels to zero indication is indicated in the drawings by the knurled thumb wheel 8. In the counting device illustrated in the drawings, the common axis of the number Wheels is parallel with the axis of the operating shaft 6.

A trigger 9 is pivoted in the frame 5 and is engaged at the rear and pressed toward its forward position by a bent leaf trigger spring 10 anchored in the frame 5. The construction of the counter-actuating mechanism and its means of control are such that the counting operation begins when the trigger is pressed rearward and-stops when it is released. 7

The number-wheel-actuating mechanism, for actuating .the units number wheel 7 from the rotative shaft 6 during a desired time interval, will now be described.

At its rear or inner end the shaft or spindle 6 is provided with an eccentric member shown as a crank pin formed by a headed screw 11. The units number wheel 7 concentrically carries a ten-tooth ratchet wheel, 12. Reverse rotation of the units number wheel 7 is prevented and'its correct positioning secured bymeans of a bent leafretaining spring 13 anchored to the frame or casing 5 and having a free end engaging the teeth of the ratchet wheel 12.

A pawl device for actuating the ratchet wheel 12 is shown as a flat slidable pawl 14 which is guided in its sliding movements by a guide pin 15 and by guide surfaces formed on the casing. 5. The pawl 14: has a free pawl end engageable with the teeth of the ratchet wheel 12 and at its other end is of greater width and in this wider portion is provided with a crank pin opening, shown as square, and of a size permitting the crank pin 11 to freely revolve in the opening without imparting movement to the pawl 14 when the crank pin opening is centered relatively to the axis of the shaft 6 (Fig. 2). The head of the crank pin 11 is too large to pass through the opening in the pawl 14 and assists in holding in place and guiding the pawl. If the slidable pawl 14 be moved from the shaft 6 toward the ratchet wheel 12, its free end will engage a tooth of the ratchet wheel and impart rotation to the ratchet wheel to the extent of one tooth, and return movement of the pawl 14 will bring it into position to engage with the next tooth of the ratchet wheel (Fig. 4). The return movement of the pawl 14 is eflected by a long coiled retractile spring 16 attached to the wider end of the pawl and anchored to the casing 5 in the handle portion thereof. The return movement of the pawl 14, effected by the return spring 16, brings the wall of the crank pin opening on the side nearest the free end of the pawl into position for engagement by the crank pin 11 (Fig. 4), so that rotation of the shaft 6 will impart positive number-wheel-aotuating movement to the pawl 14, idle return movement of the pawl 14 being effected by the return spring 16.

It will now be clear that each rotation of the shaft 6 will rotate the units number wheel 7 one step or number, so that, for example, if the device be in operation during a period of one minute, the number wheels of the counting mechanism will read in terms of or indicate directly the R. P. M. of the rotating part from which the indication is taken.

A longitudinally shiftable stop bar 17 extends parallel with the shaft 6 and is movable, at its rear end, into and out of the return path of the slidable pawl 14. The stop bar 17 is guided by guide surfaces on the casing 5 and by a headed guide pin 18 engaging in a slot near the rear end of the stop bar 17. The, trigger 9 carries a small projecting pin or stud 19 which engages in an aperture in the forward end of the stop bar 17, for sliding the stop bar forward and back. The trigger spring 10 tends to move the stop bar 17 to its rearward position, so that normally, or when the trigger 9 is left free, the rear end of the stop bar 17 will be projected into the return path of the slidable pawl 14, after a number-wheel-actuating movement of the pawl 14 by the crank pin 11, preventing return movement of the pawl 14 under the influence of the return spring 16 and maintaining the square crank pin opening in the pawl 14 concentric with the rotative shaft 6 (Figs. 1, 2 and 3), so that the shaft 6 may freely rotate without imparting movement to the pawl 14. .Manual pressure on the trigger 9 will withdraw the rear end of the longitudinally shiftable stop bar 17 out of the path of the slidable pawl 14,, permitting this pawl to be retracted by the return spring 16, so that the pawl will be brought into position to be engaged by the crank pin 11 and given positive number-wheel-actuating movement.

In using the device, the pointed end of the spindle 6 is pressed. against the center of.

the rotating part, and then, noting the time, the trigger 9 is pressed. After a desired interval of time has elapsed, say one minute or some convenient fractional part of a minute, the trigger is released, the device removed and a reading taken from the number wheels. The indication will be the number of rotations of the part actually made during the time that the trigger was held.

It is obvious that ,various modifications may be made in the construction shown in the drawings and above particularly described within the principle and scope of my invention.

I claim:

1. A revolution counter having, in combination, a number wheel, a rotative operating shaft parallel with the axis of the number wheel, a ratchet wheel rotatively carried by the number wheel, an operating member carried by the operating shaft, a pawl device engageable with the ratchet wheel and actuatable in one direction of movement by the operating member, a.

spring for imparting return movement to the pawl device, a stop bar slidable longitudinally parallel with the operating shaft into or out of the return path of the pawl device, and a spring for moving the stop bar to its pawl-engaging position when the stop bar is unrestrained, whereby the stop bar must be held in retracted position against the tension of the spring for causing the counter to operate.

2. A revolution counter comprising, in combination, a number wheel, a rotative operating shaft parallel with the axis of the number wheel, a ratchet wheel concentric with and connected to the number wheel, a. crank pin carried by the inner end of the shaft, a slidable pawl engageable with the ratchet wheel and adapted to be given number-wheel-actuating movement by the crank pin, a spring for imparting idle return movement to the pawl, a stop bar slidable longitudinally parallel with the operating shaft and shiftable into or out of the return path of the pawl, a trigger for withdrawing the stop bar from the return path of the pawl, and a spring for moving the trigger and the stop bar to the pawl-engaging position of the latter.

3. A revolution counter comprising, in combination, a number wheel, a ratchet wheel connected therewith, a rotative operating shaft, an eccentric pawl-actuating member carried by such shaft. a pawl engageable with the ratchet wheel and having therein an opening receiving and permitting free idle rotation of the eccentric memher in one position of the pawl, and a spring for moving the pawl to a position in which it will be engaged by the eccentric member.

4. A revolution counter comprising, in combination, a number wheel, a ratchet wheel connected therewith, a rotative operating shaft, an eccentric pawl-actuating member carried by such shaft, a pawl engageable with the ratchet-wheel and provided with an opening receiving and permitting free idle rotation therein of the cocentric member in the retracted position of the pawl, a pawl-retracting spring for moving the pawl to a position in which it will be engaged by and given positive numberwheel-actuating movement by the eccentric member, and a stop shiftable into or out of the path of retraction of the pawl to hold the pawl at non-operative position relative to the eccentric member or to permit the spring to move the pawl to a position where it will be operated by the eccentric member. In testimony whereof I have afiixed my signature in presence of two witnesses.

WILLIAM H. ZAOHMANN. WVitnesses:

HARRY C. LEWIS, JOHN W. WALLER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of l'stents, Washington, D. 0. 

